Apparatus for drying and heat treating material



7 F. WERNERSSON 2,040,227

APPARATUS FOR DRYING AND HEAT TREATING MATERIAL Filed May 24,.1935

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Frederik Wernersson by? ATTyS.

Patented May 12, 1936 PATENT OFFICE APPARATUS FOR DRYING AND HEAT TREATING MATERIAL Frederik Wernersson, Copenhagen, Denmark Application May 24, 1935, Serial No. 23,212

1 Claim.

This invention relates to an apparatus designed to dry and also heat treat material and it relates particularly to the type of dryingapparatus which includes a drying chamber in which the material to be treated is placed, a heating chamber communicating with opposite sides of the'drying chamber and means for causing a continuous re-circulation of the heated drying and/or heat treating medium through the drying cha ber and heating chamber.

In an app ratus of this type the drying medium moves through the drying chamber continuously in the same direction and it has been found that frequently the temperature at different parts of the drying chamber will vary by several degrees. While such variation may be unimportant when drying some materials yet for certain purposes it is frequently desirable to maintain the temperature in all parts of the drying chamber at approximately the same point especially where the material in the drying chamber is being subjected to a heat treatment as well as the drying operation. 1

As an example reference may be had to the vulcanizing process in which in order to secure satisfactory results the drying and the heat treating of the material must be carried out within temperature limits of one or two degrees. In some vulcanizing processes the material being vulcanized will be deleteriously affected if during the drying and vulcanizing operation it is subjected to a temperature above or below the relatively narrow range of one or two degrees.

It is an object of the present invention to provide a drying and/or heat treating apparatus operating-on the re-circulating principle abovementioned which. is so constructed that a tem-- perature will be maintained in all parts of the chamber which is -substantially uniform 4 and in which there is not more than one or two degrees variation between any two points in the chamber.

This object is attained by providing means for Y producing in the drying chamber a local re-cir- 45 culation of the drying medium in a direction at right angles to its general direction of travel through the drying chamber as it is re-circulated in the closed circuit formed by the drying chamber and the heating chamber. With my inven- 50 tion, therefore, the drying or heat treating medium is forced through the heating chamber whereitis heated to the desired temperature and then is introduced into the drying chamber and is moved therethrough back to the heating 66 chamber and during its travel through the drying chamber the heating medium is given a continuous re-circulating movement in a direction at right angles to its movement through the drying chamber. In this way the temperature at all points of the drying chamber is maintained uniform.

In order to give an understanding of the invention I have illustrated in the drawing a selected embodiment thereof which will now be described after which the novel features will be 1 pointed out in theappended claim.

In the drawing: Y

. Fig. 1 is a vertical sectional view through an apparatus-embodying my invention taken on substantially the line i-l, Fig. 2. 5

Fig. 2 is a section on the line 22, Fig. 1.

In the drawing, l indicates a suitable housing having within it the drying and heat treating chamber 2 and also having a heating chamber I which contains suitable heating, means herein :0 shown in the form of steam pipes 4. The heating chamber 3 communicates with the lower end of the drying chamber 2 through a passageway 5 and with the upper end of the drying chamber through apassageway 6, and there is thus estab- -25 lished a closed circuit through said chambers through which the drying medium may be continuously circulated and re-circulated as shown by the' arrows a in Fig. 1. This re-circulation of the drying medium is produced by the fan or 30 blower I which is shown as located in the upper part of the heating chamber 3 and which may be operated in any suitable way as by means of a belt pulley 8. The fan 1 operates to draw the gaseous or heat treating medium from the dry- 35 ing chamber 2 through the passage 6 and force the same through the heating chamber and over the heating pipes and thence back to the drying chamber again through the passage 5.

Where the drying medium is passed through 40 the drying chamber continuously in the same direction it frequently happens that a considerable temperature variation will develop in difierent parts of the drying chamber. To avoid this and to provide means for maintaining a uniform temperature in all parts of the drying chamber I provide auxiliary fans. or blowers 9, IO situated within the drying chamber 2 on opposite sides thereof and located out of line with each other as shown best in Fig. 2. These auxiliary fans 9, iii are constructed to produce a current of the drying medium in a direction at right angles to that in which it travels through the chamber 1 from the inlet passage 5 to the outlet passage 6. The fan I, for instance, establishes a cross-current of the drying medium from one side to the other of the chamber 2 as indicated by the arrows b and the fan l0 produces another cross-current in the opposite direction from one side to the other of the chamber 2' as indicated by the arrows c. Since these fans 9, ID are out oi alinement with each other the result is that the two fans produce a local auxiliary recirculation of the drying medium in the chamber 2 as indicated by the arrows b and c, which auxiliary re-circuthe chamber 2 a temperature in which there is no more than two degrees variation between an parts of the chamber. L

I claim:

A device for drying material with subsequent heat treatment comprising a casing divided by a vertical partition into a drying chamber and a heating chamber, said chambers communicating with each other at both the top and the bottom, heating means in the heating chamber, means to recirculate the drying medium through said chambers successively, two fans in the drying chamber on opposite sides thereof, one being located adjacent the heating chamber and the other adjacent the side of the drying' chamber opposite the heating chamber, said fans operating to direct currents of drying medium across the drying chamber in opposite directions and out of line with each other and transverse to the general recirculating movement of the drying medium through the drying chamber, thereby to form a local recirculating movement within the drying chamber in a direction at right angles to said general recirculating movement, whereby the heated medium which is delivered to the drying chamber is evenly distributed and a substantially uniform temperature is maintained throughout the drying chamber.

FREDERIK WERNERSSON. 

